The present invention relates to a lid opening mechanism for a digital audio tape (DAT) tape cassette, and particularly to a mechanism in which a cassette can be opened more easily and the load applied to the tape cassette can be reduced.
In a conventional DAT cassette, a lid opening is done in the manner described below. That is, as shown in FIG. 1, if a tape cassette 1 comes to be positioned within a tray (not shown) of a DAT deck, the tray moves inwardly, and the tape cassette 1 which is mounted on the tray is placed on a bottom plate 5 (shown in FIG. 3A) of a cassette holder 4 (FIG. 3A). At the same time, a slide plate 3 (FIG. 3A) of the tape cassette 1 is engaged with a pair of protuberances 6 (FIG. 3A) which are projected forwardly from the bottom plate 5 of the cassette holder 4. Then the cassette holder 4 descends, and, at the same time, the lower leading end of the lid 2 of the tape cassette 1 is engaged with an engaging piece 7, so that the lid 2 should be pivotally opened.
However, as shown in FIG. 1A, if an inclined face 7a is formed on the upper end of the engaging piece 7, the lower leading end of the lid 2 of the tape cassette 1 is slid along the inclined face 7a, thereby reducing the load. However, in this case, the height h of the engaging piece 7 has to be higher than the descending distance H of the cassette 1, with the disadvantageous result that the volume of the tray housing assembly is increased, and ultimately the volume of the DAT deck is increased.
In an attempt to overcome the above-described problem, in case the upper face of the engaging piece 7 is formed with a chamfered face 7b as shown in FIG. 1B, the descending distance H becomes smaller than the height h of the engaging piece 7, and the lid 2 has to pass over the inclined face 7b, with the disadvantageous result that the load is increased.